aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/wireless/libertas/rx.c
blob: 63d7e19ce9bd46f6753c15d7bafc2f2b6b48abe4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
/**
  * This file contains the handling of RX in wlan driver.
  */
#include <linux/etherdevice.h>
#include <linux/types.h>

#include "hostcmd.h"
#include "radiotap.h"
#include "decl.h"
#include "dev.h"
#include "wext.h"

struct eth803hdr {
	u8 dest_addr[6];
	u8 src_addr[6];
	u16 h803_len;
} __attribute__ ((packed));

struct rfc1042hdr {
	u8 llc_dsap;
	u8 llc_ssap;
	u8 llc_ctrl;
	u8 snap_oui[3];
	u16 snap_type;
} __attribute__ ((packed));

struct rxpackethdr {
	struct rxpd rx_pd;
	struct eth803hdr eth803_hdr;
	struct rfc1042hdr rfc1042_hdr;
} __attribute__ ((packed));

struct rx80211packethdr {
	struct rxpd rx_pd;
	void *eth80211_hdr;
} __attribute__ ((packed));

static int process_rxed_802_11_packet(struct lbs_private *priv,
	struct sk_buff *skb);

/**
 *  @brief This function computes the avgSNR .
 *
 *  @param priv    A pointer to struct lbs_private structure
 *  @return 	   avgSNR
 */
static u8 lbs_getavgsnr(struct lbs_private *priv)
{
	u8 i;
	u16 temp = 0;
	if (priv->numSNRNF == 0)
		return 0;
	for (i = 0; i < priv->numSNRNF; i++)
		temp += priv->rawSNR[i];
	return (u8) (temp / priv->numSNRNF);

}

/**
 *  @brief This function computes the AvgNF
 *
 *  @param priv    A pointer to struct lbs_private structure
 *  @return 	   AvgNF
 */
static u8 lbs_getavgnf(struct lbs_private *priv)
{
	u8 i;
	u16 temp = 0;
	if (priv->numSNRNF == 0)
		return 0;
	for (i = 0; i < priv->numSNRNF; i++)
		temp += priv->rawNF[i];
	return (u8) (temp / priv->numSNRNF);

}

/**
 *  @brief This function save the raw SNR/NF to our internel buffer
 *
 *  @param priv    A pointer to struct lbs_private structure
 *  @param prxpd   A pointer to rxpd structure of received packet
 *  @return 	   n/a
 */
static void lbs_save_rawSNRNF(struct lbs_private *priv, struct rxpd *p_rx_pd)
{
	if (priv->numSNRNF < DEFAULT_DATA_AVG_FACTOR)
		priv->numSNRNF++;
	priv->rawSNR[priv->nextSNRNF] = p_rx_pd->snr;
	priv->rawNF[priv->nextSNRNF] = p_rx_pd->nf;
	priv->nextSNRNF++;
	if (priv->nextSNRNF >= DEFAULT_DATA_AVG_FACTOR)
		priv->nextSNRNF = 0;
	return;
}

/**
 *  @brief This function computes the RSSI in received packet.
 *
 *  @param priv    A pointer to struct lbs_private structure
 *  @param prxpd   A pointer to rxpd structure of received packet
 *  @return 	   n/a
 */
static void lbs_compute_rssi(struct lbs_private *priv, struct rxpd *p_rx_pd)
{

	lbs_deb_enter(LBS_DEB_RX);

	lbs_deb_rx("rxpd: SNR %d, NF %d\n", p_rx_pd->snr, p_rx_pd->nf);
	lbs_deb_rx("before computing SNR: SNR-avg = %d, NF-avg = %d\n",
	       priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
	       priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);

	priv->SNR[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->snr;
	priv->NF[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->nf;
	lbs_save_rawSNRNF(priv, p_rx_pd);

	priv->SNR[TYPE_RXPD][TYPE_AVG] = lbs_getavgsnr(priv) * AVG_SCALE;
	priv->NF[TYPE_RXPD][TYPE_AVG] = lbs_getavgnf(priv) * AVG_SCALE;
	lbs_deb_rx("after computing SNR: SNR-avg = %d, NF-avg = %d\n",
	       priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
	       priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);

	priv->RSSI[TYPE_RXPD][TYPE_NOAVG] =
	    CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_NOAVG],
		     priv->NF[TYPE_RXPD][TYPE_NOAVG]);

	priv->RSSI[TYPE_RXPD][TYPE_AVG] =
	    CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
		     priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);

	lbs_deb_leave(LBS_DEB_RX);
}

/**
 *  @brief This function processes received packet and forwards it
 *  to kernel/upper layer
 *
 *  @param priv    A pointer to struct lbs_private
 *  @param skb     A pointer to skb which includes the received packet
 *  @return 	   0 or -1
 */
int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
{
	int ret = 0;
	struct net_device *dev = priv->dev;
	struct rxpackethdr *p_rx_pkt;
	struct rxpd *p_rx_pd;
	int hdrchop;
	struct ethhdr *p_ethhdr;
	const u8 rfc1042_eth_hdr[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

	lbs_deb_enter(LBS_DEB_RX);

	BUG_ON(!skb);

	skb->ip_summed = CHECKSUM_NONE;

	if (priv->monitormode)
		return process_rxed_802_11_packet(priv, skb);

	p_rx_pkt = (struct rxpackethdr *) skb->data;
	p_rx_pd = &p_rx_pkt->rx_pd;
	if (priv->mesh_dev && (p_rx_pd->rx_control & RxPD_MESH_FRAME))
		dev = priv->mesh_dev;

	lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
		 min_t(unsigned int, skb->len, 100));

	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
		lbs_deb_rx("rx err: frame received with bad length\n");
		dev->stats.rx_length_errors++;
		ret = 0;
		goto done;
	}

	/*
	 * Check rxpd status and update 802.3 stat,
	 */
	if (!(p_rx_pd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) {
		lbs_deb_rx("rx err: frame received with bad status\n");
		lbs_pr_alert("rxpd not ok\n");
		dev->stats.rx_errors++;
		ret = 0;
		goto done;
	}

	lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
	       skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));

	lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
		sizeof(p_rx_pkt->eth803_hdr.dest_addr));
	lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
		sizeof(p_rx_pkt->eth803_hdr.src_addr));

	if (memcmp(&p_rx_pkt->rfc1042_hdr,
		   rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
		/*
		 *  Replace the 803 header and rfc1042 header (llc/snap) with an
		 *    EthernetII header, keep the src/dst and snap_type (ethertype)
		 *
		 *  The firmware only passes up SNAP frames converting
		 *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
		 *
		 *  To create the Ethernet II, just move the src, dst address right
		 *    before the snap_type.
		 */
		p_ethhdr = (struct ethhdr *)
		    ((u8 *) & p_rx_pkt->eth803_hdr
		     + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
		     - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
		     - sizeof(p_rx_pkt->eth803_hdr.src_addr)
		     - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));

		memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
		       sizeof(p_ethhdr->h_source));
		memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
		       sizeof(p_ethhdr->h_dest));

		/* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
		 *   that was removed
		 */
		hdrchop = (u8 *) p_ethhdr - (u8 *) p_rx_pkt;
	} else {
		lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
			(u8 *) & p_rx_pkt->rfc1042_hdr,
			sizeof(p_rx_pkt->rfc1042_hdr));

		/* Chop off the rxpd */
		hdrchop = (u8 *) & p_rx_pkt->eth803_hdr - (u8 *) p_rx_pkt;
	}

	/* Chop off the leading header bytes so the skb points to the start of
	 *   either the reconstructed EthII frame or the 802.2/llc/snap frame
	 */
	skb_pull(skb, hdrchop);

	/* Take the data rate from the rxpd structure
	 * only if the rate is auto
	 */
	if (priv->enablehwauto)
		priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);

	lbs_compute_rssi(priv, p_rx_pd);

	lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
	dev->stats.rx_bytes += skb->len;
	dev->stats.rx_packets++;

	skb->protocol = eth_type_trans(skb, dev);
	if (in_interrupt())
		netif_rx(skb);
	else
		netif_rx_ni(skb);

	ret = 0;
done:
	lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
	return ret;
}
EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);

/**
 *  @brief This function converts Tx/Rx rates from the Marvell WLAN format
 *  (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
 *
 *  @param rate    Input rate
 *  @return 	   Output Rate (0 if invalid)
 */
static u8 convert_mv_rate_to_radiotap(u8 rate)
{
	switch (rate) {
	case 0:		/*   1 Mbps */
		return 2;
	case 1:		/*   2 Mbps */
		return 4;
	case 2:		/* 5.5 Mbps */
		return 11;
	case 3:		/*  11 Mbps */
		return 22;
	/* case 4: reserved */
	case 5:		/*   6 Mbps */
		return 12;
	case 6:		/*   9 Mbps */
		return 18;
	case 7:		/*  12 Mbps */
		return 24;
	case 8:		/*  18 Mbps */
		return 36;
	case 9:		/*  24 Mbps */
		return 48;
	case 10:		/*  36 Mbps */
		return 72;
	case 11:		/*  48 Mbps */
		return 96;
	case 12:		/*  54 Mbps */
		return 108;
	}
	lbs_pr_alert("Invalid Marvell WLAN rate %i\n", rate);
	return 0;
}

/**
 *  @brief This function processes a received 802.11 packet and forwards it
 *  to kernel/upper layer
 *
 *  @param priv    A pointer to struct lbs_private
 *  @param skb     A pointer to skb which includes the received packet
 *  @return 	   0 or -1
 */
static int process_rxed_802_11_packet(struct lbs_private *priv,
	struct sk_buff *skb)
{
	int ret = 0;
	struct net_device *dev = priv->dev;
	struct rx80211packethdr *p_rx_pkt;
	struct rxpd *prxpd;
	struct rx_radiotap_hdr radiotap_hdr;
	struct rx_radiotap_hdr *pradiotap_hdr;

	lbs_deb_enter(LBS_DEB_RX);

	p_rx_pkt = (struct rx80211packethdr *) skb->data;
	prxpd = &p_rx_pkt->rx_pd;

	// lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100));

	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
		lbs_deb_rx("rx err: frame received with bad length\n");
		dev->stats.rx_length_errors++;
		ret = -EINVAL;
		kfree_skb(skb);
		goto done;
	}

	/*
	 * Check rxpd status and update 802.3 stat,
	 */
	if (!(prxpd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) {
		//lbs_deb_rx("rx err: frame received with bad status\n");
		dev->stats.rx_errors++;
	}

	lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
	       skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));

	/* create the exported radio header */

	/* radiotap header */
	radiotap_hdr.hdr.it_version = 0;
	/* XXX must check this value for pad */
	radiotap_hdr.hdr.it_pad = 0;
	radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
	radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
	if (!(prxpd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK)))
		radiotap_hdr.flags |= IEEE80211_RADIOTAP_F_BADFCS;
	radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
	/* XXX must check no carryout */
	radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;

	/* chop the rxpd */
	skb_pull(skb, sizeof(struct rxpd));

	/* add space for the new radio header */
	if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
	    pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
		lbs_pr_alert("%s: couldn't pskb_expand_head\n", __func__);
		ret = -ENOMEM;
		kfree_skb(skb);
		goto done;
	}

	pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr));
	memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));

	/* Take the data rate from the rxpd structure
	 * only if the rate is auto
	 */
	if (priv->enablehwauto)
		priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);

	lbs_compute_rssi(priv, prxpd);

	lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
	dev->stats.rx_bytes += skb->len;
	dev->stats.rx_packets++;

	skb->protocol = eth_type_trans(skb, priv->rtap_net_dev);
	netif_rx(skb);

	ret = 0;

done:
	lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
	return ret;
}